Moved from Pepsini.

Hi, Ken-ichi.

The info in the posts below will clarify terminology and ID criteria referred to in the comments that follow:

       

A careful inspection of the wing venation in your image above (e.g. zooming in on the full-size version) indicates the radial vein (bounding the far end of the marginal cell) meets the wing edge transversely at an acute angle (with the angle opening towards the base of the wing). In Pepsis, the distal end of the radius vein bends backwards forming a rounded tip for the marginal cell and meeting the wing edge in an acute angle opening towards the tip of the wing. That eliminates Pepsis here.

Also, it seems clear that the 1st recurrent vein meets the 2nd submarginal cell here quite far out along its posterior edge, again eliminating Pepsis, and indicating either Hemipepsis or Entypus...hard to say from the wing venation resolution in the image, but looks closer to the latter to me.

But regardless of exactly how close the tip of the 1st recurrent vein is to the distal end of the posterior margin of the 2nd submarginal cell...in reviewing Townes(1957) treatments of Hemipepsis and "Priocnemioides" (= Entypus), it appears we have no Hemipepsis in CA with orange antennae, and just one Entypus with that character...namely E. unifasciatus californicus.

Moved from Spider Wasps.

Moved from Tarantula Hawks.

The first discal cell is too long for that genus. The strong blue iridescence suggests that it is not Hemipepsis. Difficult to say for sure, but it is probably Entypus.